1. Technical Field
The present invention relates to an image system lens assembly. More particularly, the present invention relates to a compact image system lens assembly applicable to electronic products.
2. Description of Related Art
In recent years, with the popularity of mobile products with camera functionalities, the demand for miniaturizing a photographing lens assembly is increasing. The sensor of a conventional photographing camera is typically a CCD (Charge-Coupled Device) image sensor or a CMOS (Complementary Metal-Oxide Semiconductor) sensor. As advanced semiconductor manufacturing technologies have allowed the pixel size of sensors to be reduced and compact photographing lens assemblies have gradually evolved toward the field of higher megapixels, there is an increasing demand for photographing lens assemblies featuring better image quality.
A conventional compact optical lens system employed in a portable electronic product such as disclosed in U.S. Pat. No. 7,869,142, mainly adopts a four-element lens structure. Due to the popularity of mobile products with high-end specifications, such as smart phones and PDAs (Personal Digital Assistants), the higher pixel and image-quality requirements of the compact optical lens system have increased rapidly. However, the conventional four-element lens structure cannot satisfy the requirements of the compact optical lens system.
Although other conventional optical lens system with five-element lens structure such as disclosed in U.S. Pat. No. 8,000,030 and U.S. Pat. No. 8,000,031 which provide better image quality and higher resolution. However, the object side of the optical lens system does not have a configuration of two lens elements that one has negative refractive power and the other has stronger positive refractive power. Thus, the field of view of the optical lens system cannot be enlarged, and the total track length thereof cannot be reduced. Meanwhile, the aberration and the distortion of the optical lens system cannot be eliminated.